This invention generally relates to a carrier in an axle assembly of a motor vehicle. More specifically, this invention relates to a carrier made of aluminum reinforced with ceramic particles installed in the axle assembly of a motor vehicle.
Most vehicles use at least one gearset to transfer torque between rotating shafts or other components that rotate around different axes. For example, the axle of a rear wheel drive vehicle includes a pinion gear rotating around a generally longitudinal axis and driven by torque from the transmission coupled to a ring gear which rotates around a generally transverse axis and drives torque into the differential. In the case of some four wheel drive vehicles with transverse-mounted engines, a perpendicular axis or skew axis gearset within a power take-off unit is used to transfer torque from the transverse axis of the engine and transmission to the longitudinal axis of a driveshaft
Typically, the carrier that supports the differential case and the gear set is made of magnesium, aluminum or cast iron. The gears themselves are made of steel. Typically, these gearsets are sensitive to changes or inaccuracies in the positions of the gears. Even small deflections can lead to noise and premature gear failure. Since the operating temperatures are relatively high, differences in thermal expansion between the carrier and the gears can lead to such deflections as the temperature of the axle assembly changes. Applications in which the temperature range is expected to be broad must then use in the carrier a material with low thermal expansion, such as cast iron. The use of cast iron makes the axle assembly heavy.
In the present invention, a carrier made of an aluminum reinforced with ceramic particles allows for a lower thermal expansion and for a stable carrier in the axle assembly. Further, the low thermal expansion of the carrier reduces the deflection and prevents noise and premature failure of the gearsets. In addition, the carrier made of aluminum matrix reinforced with ceramic particles is much lighter thereby reducing the overall weight of the motor vehicle.